Electric switches equipped with fuse means

ABSTRACT

A switch having at least one pair of fixed contacts and at least one pair of movable contacts adapted to cooperate with these fixed contacts, the movable contacts are connected with each other by fuse means and they are supported together with these fuse means by a supporting plate which is movable between a closed position nearest to the fixed contacts and an open position farthest to the said fixed contacts. When at the open position the supporting plate may be turned on itself through 180* so as to bring the fuse means on what is now its outer side, where they are separated from the live parts of the switch by the supporting plate itself. The switch may then be brought to an ineffective closed position for which the supporting plate wholly covers the fixed contacts and forms a closure for the open side of the switch casing. The fuse means of each pair are preferably in the form of a removable fuse cartridge having end blades which constitute the movable contacts.

United States Patent [191 Chambon 1 July 24, 1973 ELECTRIC SWITCHESEQUIPPED WITH FUSE MEANS [75] Inventor: Michel Chambon, Rhone, France[73] Assignee: Lucien Ferraz & Cie, Lyon, France [22] Filed: June 26,1972 [21] Appl. N0.: 266,394

[52] US. Cl 337/9, 317/1-16, 337/144, 337/146, 337/149 [51] Int. Cl.1101b 85/22 [58] Field of Search 337/6, 7, 8, 9, 142, 337/143, 144, 145,146, 149;317/114, 116; 200/50 R [56] I References Cited UNITED STATESPATENTS 3,688,237 8/1972 Orost, Jr. et al 337/7 3,614,697 10/1971 Dunhamet al. 337/6 3,579,045 5/1971 Keogh 337/116 X 3,346,711 10/1967 Rys eta1... 337/9 3,280,280 10/1966 Gryctko 337/6 3,510,817 5/1970 Flick etal..... 337/6 3,211,859 1 0/1965 Kobryner 337/9 X 1,424,579 Mason 337/9Primary Examiner-Bemard A. Gilheany Assistant Examiner-A. T. GrimleyAttorney-Arthur E. Dowell, Jr. et al.

[57] ABSTRACT now its outer side, where they are separated from the liveparts of the switch by the supporting plate itself. The switch may thenbe brought. to an ineffective closed position for which the supportingplate wholly covers the fixed contacts and forms a closure for the openside of the switch casing.

The fuse means of each pair are preferably in the form of a removablefuse cartridge having end blades which constitute the movable contacts.

8 Claims, 12 Drawing Figures PAIENIEU JUL 4 ma SHEET 1 OF 5 PAIENniu LwmSHEEI 2 [IF 5 ELECTRIC SWITCHES EQUIPPED WITH FUSE MEANS The presentinvention relates to switches equipped with fuse cartridges.

Such switches are generally so arranged that the fuse cartridges canonly be removed and exchanged when the mechanical contacts of the switchare open. But of course the operator should take care not to touch liveparts adjacent to the cartridges.

It is an object of the present invention to provide a switch of the kindabove referred to in which the fuse cartridges may be brought to aposition wholly exterior to the switch casing itself, in such mannerthat they may be removed or replaced without any risk for the operator.

In accordance with the invention the fuse cartridges are carried by amovable'supporting plate, their end blades cooperating with fixedcontacts carried by a stationary base frame so as to form themovablecontacts of the switch, and at the open position of the latter, i.e.,when the movable supporting plate is farthest from the fixed contacts,the said supporting plate may be turned through 180,in such manner thatthe fuse cartridges may be situated on what is now the outer side of thesaid supporting plate. The supporting plate may be locked at thisoverturned position and its actuating mechanisms may again be operatedto bring it to its position nearest to the fixed contacts for which itsubstantially covers the latter. Th'eoperator may then access to thefuse cartridges without any risk of touching live parts. At thisposition the supporting plate may evenform the closing member of acasing surrounding the live parts of the switch which are thus whollyunaccessible.

I In the annexed drawings:

FIG. 1 is a perspective view of an embodiment of a disconnecting switchaccording to the invention, the parts being illustrated at the closedposition of the switch. i FIG. 2 is a view similar to FIG. 1, butshowing the switch at the open position.

FIG. 3 reproduces FIG. 2, but with the movable supporting plateoverturned to expose the fuse cartridges.

FIG. 4 also shows the switch with its movable supporting plateoverturned, but after the said plate has been m'ovedtowards the fixedcontacts of the switch, i.e., when the switch has been ineffectivelyclosed.

FIG. 5 is a longitidunal section taken along line V-V of FIG. 1.

FIG. 6 is an exploded perspective view showing the detail of oneof thesecuring devices by means of which thefuse cartridges are attached tothe movable supporting plate.- l I FIG. '7 is an enlarged sectionshowing the detail of the device by means of which the movablesupporting plate may be locked with one of its actuating carriages.

FIG. 8 is a detailed section of the locking system for the actuatinglever of the switch.

FIG. 9 is an enlarged fragmental view in elevation illustrating theauxiliary pre-rupturing contact system associated to the main contactsof the switch.

FIG. 10 is an exploded perspective view showing the essential members ofthis last system.

FIG. 11 indicates in a very diagrammatical manner how an arcextinguishing device may be associated with the main contacts of theswitch.

FIG. 12 shows a modified embodiment of the actuating means of theswitch.

The switch illustrated in FIG. 1 comprises a frame formed of two lateralcasings I and 2 which are appropriately connected with each other by twostays 3 (FIG. 5). These casings have turned edges such as 1a adaptedtobe secured to suitable supports, such as C-shaped irons 4. Each casingcontains a quick-acting mechanism, these mechanisms being operated by acommon transverse shaft 5 which may be actuated by a lateral hand lever6.

Insulating blocks 7 (FIG. 5) are mounted on each stay 3, each of theseblocks carrying one of .the fixed contacts 8 of the main contact systemof the switch. The fixed contacts 8, which may be of any suitable type,are adapted to cooperate with the terminal blades 9 of the fusecartridges 10 which thus complete the circuit between the sets of fixedcontacts respectively carried by stays 3.

The fuse cartridges 10 are attached to a movable supporting plate 11, ofsubstantially rectangular shape, made of an appropriate insulatingmaterial and having each of its lateral sides connected with a carriageI2 slidable in guides lb, 2b provided in the facing sides of casings land 2. In FIG. 2 wherein the outer side of casing 1 is in part broken,it may be seen that carriage I2 is pivotally connected with a connectingrod 13 actuated by the corresponding quick-acting mechanism. It will beunderstood that with such an arrangement actuation of lever 6 causessupporting plate to move in a di rection perpendicular to the plane ofstays 3 (or of irons 4) between a closed position for which the terminalblades of fuse cartridges l0 engage fixed contacts 8 (position of FIGS.1 and 5) and an open position for which these terminal blades are spacedfrom the said fixed contacts (position of FIG. 2).

Each fusecartridge is removably secured'to supporting plate 11 by meansof the lugs 14 conventionnally provided at each end of the body of suchcartridges. For this purpose, and as shown in'FIG. 6, plate 11 is formedin front of each lug such as 14, with a recess 11a which contains ablade spring 15 having the shape of an (I. The rectangular opening ofrecess 11a receives a cover 15 having an aperture 16:; in the form of abutton hole, comprising a wider portion for passage of lug -l4 and anarrower portion the width of which corresponds to the distance betweenthe bottoms of two opposed lateral notches l4a provided in the said lug.The two lugs of each cartridge are pushed into the wider portion of theapertures 16a of the corresponding covers, whereby they enter thecentral portion of the corresponding springs 15, and they arethereafterpushed longitudinally into the narrower portion of apertures 16a whilespreading apart the branches of the spring between which they arethusresiliently retained.

It will be noted that supporting plate llj'includes in front of thecentral portion ofe'achfuse cartridge 10 a window 11c through which .thecartridge body may be seen, as for instance for checking the indicationswhich may be printedthereon, or for observingthe lateralindicator buttonprovided in some types of fuse cartridges to indicate that the fusibleelements have blown. Windows 11c are protected by transparent plates 17.

It is known thatin other types of cartridges the indicator membercomprises a tube which protrudes longitudinally from one of the heads ofthe cartridge in order to actuate a microswitch or like alarm contact.In such a case the cartridge should be correctly mounted on supportingplate 11 with its indicator in front of the corresponding micro-switch.For this purpose the supporting plate 11 is provided with inwardlyprotruding fingers 11d (see FIGS. 3 to 5) which form abutments for theindicators and thus prevent any incorrect mounting of the cartridges. Asto the micro-switches adapted to be actuated by these indicators, theyhave not been illustrated, but it will be understood that they may bemounted on blocks 7, or preferably on an additional stay appropriatelydisposed between casings 1 and 2.

The supporting plate 11 is so mounted on carriages 12 that it may berotated through 180 about a transverse axis. For this purpose it ispivoted to the said carriages by means of co-axial trunnions 18 securedto the said plate and rotatably supported in bearings provided incarriages 12. One of the latter further carries a button 19 (FIG. 7)urged towards plate 11 by a spring 20 mounted in a bore 12b of thecarriage and which bears against a shoulder 19a of the button rod, thisshoulder being slidably guided within bore 12b along an axis parallel tobut spaced from the axis of rotation of plate 11. Under the action ofspring 20, the end of button 19 is maintained in a blind hole lleprovided in plate 11 and it thus acts as a bolt to lock plate 11 withrespect to the carriage. Plate 11 is further formed with a recess havingan oblique bottom 11 f which may act as a ramp to push back the end ofbutton 19 against spring 20 when plate 11 is rotated about trunnions 18,so as to automatically lock the plate in position with respect to thecarriage. In order that plate 11 may be locked at two positions situatedat 180 from each other (position of FIG. 2 and position of FIG. 4), thesaid plate is formed with two bores lle and with two correspondingrecesses 11f.

In normal operation the supporting plate 11 is locked with respect tocarriages 12 at such a position that the blades 9 of fuse cartridge 10may cooperate with the fixed contacts 8. This corresponds to theposition of plate 11 in FIGS. 1, 2, 5 and 7. When on the contrary it isdesired to have access to the fuse cartridges, the switch is firstbrought to the open position of FIG. 2 so as to disengage the cartridgeblades 9 from the fixed contacts 8, button 19 is pulled laterally toliberate plate 11 and the latter is rotated through 180 about trunnions18 until it is again locked by button 19 at the overturned position ofFIG. 3. The cartridges are now wholly exposed and they may be freelyremoved and replaced without any risk for the operator.

It is furthermore to be noted that when the supporting plate 11 has thusbeen overturned, lever 6 may be actuated to bring the switch to what isnormally its closed position, the supporting plate being brought to itsposition nearest to the fixed contacts 8, as shown in FIG. 4. It isobvious that since the cartridges are now on the outer side of plate 11,their blades can no more cooperate with the fixed contacts. In otherwords the switch is ineffectively closed, its circuits being actuallyopen. If the actuating mechanism is locked at such a position, it isimpossible for an unauthorized person to rotate the supporting plate.The electric lines controlled by the switch are thus fully safe for anymanual operation.

FIG. 8 shows the detail of a possible embodiment for locking theactuating lever 6 by means of a padlock. Lever 6 is formed with a recess6a on its inner side adjacent shaft 5, this recess opening towardscasing I. A substantially flat bolt 21 is slidably guided in recess 6a,as for instance by elongated projections 6b and provided thereon. Thisbolt has a protruding tooth 21a and it extends upwardly in the form of alateral actuating lug 21b. A spring 22 attached to bolt 21 and to thelateral wall of recess 6a urges the said bolt into the recess (i.e.,towards the right in FIG. 8). Casing l carries a lateral plate 23 formedwith two slots such as 23a disposed in front of the respective endpositions of lever 6. Lever 6 further has a transverse hole 6d whichcrosses the bottom of recess 6a.

Under the action of spring 22 bolt 21 is normally maintained at itsinoperative position for which tooth 210 does not protrude towardscasing l and plate 23. But by acting on lug 21b it is possible to pushthe said bolt towards the left in FIG. 8 against the action of spring 22and thus to drive tooth 21a into one of slots 23a. If now a padlock ispassed through hole 6d, bolt 21 is maintained in position and lever 6remains locked.

The system of auxiliary pre-rupturing contacts illustrated in FIGS. 9and 10 comprises a cam 25 mounted on shaft 5 within casing 2 to act onthe turned edge 26a of a slide 26 which is guided in a directionparallel to that of carriages 12 (or horizontally in FIGS. 1 to 5).There is provided for this purpose a fixed plate 27 having twoprotruding lugs 27a which retain slide 26 laterally. Slide 26 is furtherformed with an elongated rectangular aperture 26b in which a compressionspring 28 is disposed. The latter takes rest against a tooth 27b raisedfrom plate 27 and which passes through aperture 26b to complete theguiding of the slide. Slide 26 actuates an insulating support 29 whichcarries movable contacts 30 adapted to cooperate with fixed contacts 31mounted on an insulating base 32 secured in any appropriate manner notshown to plate 27 or to its protruding lugs 27a. These contacts areprotected by a transparent cover 33. In the example illustrated support29, of elongated rectangular shape, is slidably guided by cover 33 andit is connected with slide 26 by a pin 29a secured to the said supportand engaged into a hole 260 of the slide.

As aforesaid, lever 6 actuates carriages 12 through quick-actingmechanisms not illustrated. Such a mechanism comprises in theconventional manner a spring which the driving member of the mechanismcompresses or extends until the said spring is permitted to act on thedriven member to snap same from one of its positions to the other. Thereexists therefore for lever 6 an initial period during which it rotatesshaft 5 without actuating carriages 12. Cam 25 is so arranged that itmoves slide 26 during this initial period to close the auxiliarycontacts 30-31. The circuits controlled by these contacts are thereforealready closed when the main contacts of the switch (i.e., blades 9 andcontacts 8) open. Auxiliary contacts 30-31 are used to actuate a circuitbreaker disposed in series with the present switch. With such anarrangement the switch always opens under no load condition and its maincontacts 9 and 8 can never be damaged in spite of their low rupturingcapacity.

When it is desired to increase this rupturing capacity, it is possibleto secure to the switch frame, between the fixed contacts 8 and thesupporting plate 11, a number of small spaced parallel plates 34 (FIG.11) formed with slots 34a for passage of blades 9. When the switchopens, blades 9 pass through slots 34a as soon as they are disengagedfrom contacts 8, in such manner that the electric arc which appearsbetween the blades and the fixed contacts is effectively cooled byplates 34 and is therefore rapidly extinguished. Of course plates 34should be metallic and appropriately insulated from each other and fromthe switch frame.

FIG. 12 illustrates a modification wherein shaft 5 carries a conicaltoothed segment 35 which meshes with another corresponding segment 36mounted on a lateral shaft 37 rotatably supported by a bracket 38, thesaid shaft carrying an actuating hand wheel 39. Such an arrangement,which dispenses with lever 6, may be of advantage when it is desired toactuate the switch from the front or from the rear in FIG. 1.

The poles of the switch are preferably protected by transparent covers,respectively 40, 41, which may be removably supported by lateral plates42. These covers may extend somewhat under the movable supporting plate11 in which case they are provided with slot such as 40a for passage ofblades 9. When the switch is ineffectively closed" (FIG. 4), thesupporting plate 11 plays the role of a front cover for the casingformed by covers 40, 41 and plates 42, whereby the live parts of theswitch are wholly enclosed and protected.

I claim:

1. An electric switch comprising:

' a frame;

at least one pair of fixed contacts carried by said frame, said fixedcontacts being insulated from each other; a

at least one pair of movable contacts insulated from each other, torespectively cooperate with said fixed contacts;

fuse means to connect with each other the contacts of said pair ofmovable contacts;

a movable supporting plate to support said movable contacts and saidfuse means, said plate having a first side and a second side;

attaching means to attach said movable contacts and said fuse means tosaid first side of said movable supporting plate;

driving means on said frame to displace said moveable supporting platebetween a closed position nearest to said fixed contacts and an openposition farthest from same;

pivoting means to pivotally connect said supporting plate to saiddriving means; and

locking means to lock said supporting plate with respect to said drivingmeans at a first orientation for which said first side of said platefaces said fixed contacts in such manner that said movable contacts mayengage said fixed contacts at said closed position of said plate and bespaced from same at said open position of said plate, and a secondorientation at substantially from said first orientation, and for whichsaid movable contacts are separated from said fixed contacts by saidsupporting plate at both said closed and open positions of same.

2. In a switch as claimed in claim 1, said fuse means being in the formof a fuse cartridge having a pair of opposed terminal blades, with saidblades forming said movable contacts.

3. In a switch as claimed in claim 2, said fuse cartridge having a bodyintermediate said terminal blades, said attaching means being interposedbetween said body and said supporting plate.

4. In a switch as claimed in claim 3, said attaching means comprisinglugs carried by said cartridge body and resilient clamping memberscarried by the first side of said supporting plate to removably retainsaid lugs.

5. In a switch as claimed in claim 1, said movable supportingplate beingmade of an insulating material.

6. In a switch as claimed in claim 1, said pair of fixed contactsdefining a longitudinal axis and said driving means comprising:

a pair of movable lateral carriages disposed each side of said fixedcontacts with said pivoting means being'co-axially interposed betweensaid supporting plates and each of said carriages and with said lockingmeans being interposed between said supporting plate and one at least ofsaid carriages;

means to guide said carriages along substantially parallel pathssubstantially perpendicular to the longitudinal axis of said pair offixed contacts; and

actuating means to actuate both carriages in unison.

7. In a switch as claimed in claim 6, said pivoting means defining anaxis of rotation for said supporting plate on said carriages; and saidlocking means comprising bolt means slidably movable on said one of saidcarriages along a line substantially parallel to and spaced from saidaxis of rotation,-resilient means to urge said bolt means towards saidsupporting plate, and depressions provided in said plate to cooperatewith said bolt means at said first and second orientations of saidplate. 1

8. In a switch as claimed in claim 1, said frame embodying a casinghaving an open side and said plate closing said open side of said casingwhen at said second orientation and at said closedposition.

"UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. DatedJuly 24, 1973 Inventor s) MICHEL CHAMBON It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

In vthe heading of the patent (first column) between lines 6 and 7insert:

[30] Foreign Application Priority Date July 5, 1971 France 71.25391Signed and sealed this 20th day of November 1973.

(SEAL) Attest:

RENE D. IEG TI IE JYER Acting Commissioner of Patents EDWARD M.FLETGHIR,JR. Attesting Officer RM PC4050 (10-69) USCOMM-DC 60376-P69 w u.s.GOVERNMENT PRINTVNG OFFICE: 1969 o3e6-334 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 3,748, 619 Dated July 24, 1973Inventor (s) MICHEL CHAMBON It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the heading of the patent (first column) between lines 6 and 7insert:

[30] Foreign Application Priority Date July 5, 1971 France e 71.25391Signed and sealed this 20th day of November 1973.

(SEAL) Attest:

EDWARD M.FLETGHER,JR. RENE D. TEGTl [EYER Attesting Officer ActingCommissioner of Patents FORM PO-1050 (10-69) USCOMM-DC 60376-P59 9 U.SGOVERNMENT PRINTING OFFICE: 1969 O366-334

1. An electric switch comprising: a frame; at least one pair of fixedcontacts carried by said frame, said fixed contacts being insulated fromeach other; at least one pair of movable contacts insulated from eachother, to respectively cooperate with said fixed contacts; fuse means toconnect with each other the contacts of said pair of movable contacts; amovable supporting plate to support said movable contacts and said fusemeans, said plate having a first side and a second side; attaching meansto attach said movable contacts and said fuse means to said first sideof said movable supporting plate; driving means on said frame todisplace said moveable supporting plate between a closed positionnearest to said fixed contacts and an open position farthest from same;pivoting means to pivotally connect said supporting plate to saiddriving means; and locking means to lock said supporting plate withrespect to said driving means at a first orientation for which saidfirst side of said plate faces said fixed contacts in such manner thatsaid movable contacts may engage said fixed contacts at said closedposition of said plate and be spaced from same at said open position ofsaid plate, and a second orientation at substantially 180* from saidfirst orientation, and for which said movable contacts are separatedfrom said fixed contacts by said supporting plate at both said closedand open positions of same.
 2. In a switch as claimed in claim 1, saidfuse means being in the form of a fuse cartridge having a pair ofopposed terminal blades, with said blades forming said movable contacts.3. In a switch as claimed in claim 2, said fuse cartridge having a bodyintermediate said terminal blades, said attaching means being interposedbetween said body and said supporting plate.
 4. In a switch as claimedin claim 3, said attaching means comprising lugs carried by saidcartridge body and resilient clamping members carried by the first sideof said supporting plate to removably retain said lugs.
 5. In a switchas claimed in claim 1, said movable supporting plate being made of aninsulating material.
 6. In a switch as claimed in claim 1, said pair offixed contacts defining a longitudinal axis and said driving meanscomprising: a pair of movable lateral carriages disposed each side ofsaid fixed contacts with said pivoting means being co-axially interposedbetween said supporting plates and each of said carriages and with saidlocking means being interposed between said supporting plate and one atleast of said carriagEs; means to guide said carriages alongsubstantially parallel paths substantially perpendicular to thelongitudinal axis of said pair of fixed contacts; and actuating means toactuate both carriages in unison.
 7. In a switch as claimed in claim 6,said pivoting means defining an axis of rotation for said supportingplate on said carriages; and said locking means comprising bolt meansslidably movable on said one of said carriages along a linesubstantially parallel to and spaced from said axis of rotation,resilient means to urge said bolt means towards said supporting plate,and depressions provided in said plate to cooperate with said bolt meansat said first and second orientations of said plate.
 8. In a switch asclaimed in claim 1, said frame embodying a casing having an open sideand said plate closing said open side of said casing when at said secondorientation and at said closed position.